I have Selkirk DSP double-wall pipe connecting the stove to the chimney. I know a probe-type thermometer is suggested for this setup to check flue gas temps. I'm wondering, is there a general rule-of-thumb on using an IR thermometer on the outer wall to make an estimate of the inner flue temp? Most double-wall has about 1/2" air gap between walls, and the DSP is right around there, maybe 3/8". Most of the time, I get readings like this: Cat temp: ~1200 F (probe) Stove top: ~500 F (IR) 24" up on DSP pipe: 165 F (IR) Just curious. Given that the general rule-of-thumb on single wall pipe is to double the reading on a magnetic thermo to get the inner gas temps, what would a good estimate be for double wall pipe? Thanks!
Next time I run the stove I will put a magnetic thermometer next to my probe meter and take some pictures. I could make a good arguement, however, that you probably don’t care about surface temp so why bother measuring it? Sometimes the temp lags as a product of time and other external factors. Any correlation would be better measured with calculus. I’m not nearly that smart. When we would tune forced induction cars it was always really dangerous to rely on estimates of pressure or temps. We always wanted sensors and gauges that measured the actual real thing.
I'd suggest a probe thermometer. I just switched to ICC double wall and put a probe in it. Drill a 3/16" hole and a 1/4" hole on the outside and put it in the pipe. No more guessing and you will feel more confident running the stove up to temp and controlling air the process. Too hard to judge based on outer wall temps. I was seeing 500 degrees internal with 165 degree outside temp. Probably different with Selkirk. Another thing to check is the accuracy of the probe. I verified the probe was correct with my digital thermometer. Keep warm! Last night was a rough one with single digits and a strong northwest wind.
Real world data: I’m not seeing any real purpose in watching surface temps of a double wall pipe. The range is so limited. Sorry my stack temps don’t go very high. Ideal Steel and all. I might have been able to get them a ‘lil higher but I need a restart on a coal bed.
I wish the range was more defined on the fluegard. I double checked mine with a digital and loosed the nut up and spun it to match. I'd say it was reading 100 degrees cooler before adjusting it.
yes if you look at it close, the second dot up is the 400 mark. You logically think the 400 mark is the separation line. I spun mine so that when its at 400 its right on the separation line when comparing it to my digital temp thermometer. These cat stoves on low run pretty darn cool on stack temps.
Hi Qyota. I also have the DSP. I vent to the rear, directly into a cleanout, then straight up. With the stove in a steady state, ST ~550, internal Auber probe 18" above ST, at 400-410, IR gun on outside of DSP shows 180-190. As you probably know, the outside temp can vary 5-10 degrees depending on which side of the pipe you measure.
